1. Field of the Invention
The present invention relates to an image forming apparatus and method which are used to form an image on a sheet such as a transfer sheet.
2. Description of the Related Art
In a conventional image forming apparatus typified by a copying machine, when a plurality of originals are to be copied, they are copied from the last original, and each transfer sheet is discharged out of the machine with its image-bearing surface facing up. According to this copying method, the order of output sheets output outside the machine is kept the same as that of the originals by starting copying from the last original.
A composite copying machines having both printer and FAX functions has recently been developed. When this composite copying machine functions as a printer, information to be output is sequentially processed from the first page. As a result, the order of output sheets output out of the machine is reversed. For this reason, a mechanism of discharging sheets upon reversing them is added to the output unit of the copying machine to correct the order of output sheets by reversing/outputting them.
When the sheet reversing mechanism mounted on the output unit of the conventional copying machine is to be used, a sheet must be conveyed along a guide with a curvature, resulting in damage to the sheet. This makes it difficult to convey a sheet or damages the sheet depending on the type of sheet. When a sheet like an OHP sheet is used, the quality of the image formed on the sheet deteriorates owing to damage to the sheet.